A. Field of Invention
The present invention relates to plastic cards that are carried by individuals, such as credit cards, security cards, smart cards, loyalty cards, phone cards, and the like. More specifically, the present invention relates to a transparent and/or translucent card that can block infrared light while allowing visible light to pass through the card, and that includes three-dimensional graphics that take advantage of the transparent/translucent properties of the card.
B. Related Art
Credit cards, bank cards and other like cards have become more popular as is the applications for these types of cards has increased. Producers and manufacturers of these cards have further attempted to produce various designs on the cards to attract users of these cards.
Along these lines, there is a desire in the plastic card industry to produce a clear or otherwise transparent plastic card. The cards introduced so far, however, still block visible light to some degree, rather than being truly transparent. This is because the potential uses for a transparent card have been limited due to its inability to be detected by infrared (IR) sensors. For instance, most readers that are used in banking applications, e.g. ATM machines, employ IR sensors to detect the presence of a card in the reader. These sensors depend upon the card to block the path of an IR light beam. Since infrared light passes through a non-opaque card, the reader fails to detect when a card is inserted into it, which can frustrate users who are not able to complete transactions with the card. To be detectable, cards should have an opacity greater than 1.3 optical density for light in the range of wavelengths that include at least 700-1000 nm (the end of the visible range and the beginning of the near infrared range), pursuant to current ISO standards that apply to plastic cards. Clear cards which have been proposed to date do not meet this requirement.
In addition to readers, IR sensors are used throughout the card manufacturing process to detect the presence of a card, or core stock from which cards are made, at numerous locations. Again, a non-opaque material renders these sensors ineffective for their intended purpose.